Tree stand



FIG. 1 is a top plan view of a tree stand showing our new design;

FIG. 2 is a side elevation view thereof;

FIG. 3 is a side perspective view thereof; and,

FIG. 4 is another side perspective view thereof, with a tree being shown in broken lines for illustrative purposes only and forming no part of the claimed design. 

The ornamental design for a tree stand, as shown and described. 